In a communication system including a transmit and receive path and a receive-only path, methods for measuring receive sensitivities of the respective paths have been developed in order to measure performance of the paths.
It is relatively easy to measure the receive sensitivity of the transmit and receive path while the communication system provides services, since the transmit and receive path can communicate with a device for measuring the receive sensitivities.
However, since the receive-only path has no transmission function, it is not easy to measure the receive sensitivity of the receive-only path while the communication system provides services, and it is not easy to measure the receive sensitivity thereof when the communication system provides no services.
An exemplified communication system having a general transmit and receive path and a receive-only path is a mobile communication base station which manages three or less FAs (Frequency Assignments).
The mobile communication base station has two paths A and B as a default, and the path A services 3FA, 5FA, and 7FA, and the path B services 1FA, 2FA, 4FA, and 6FA in the general manner. Therefore, the paths A and B have the transmission and receiving functions when they service three or more FAs. However, in the case of servicing three or less FAs, the path A manages transmission and receiving of three FAs, and the path B includes a receive-only path for diversity of the path A.
FIG. 1 shows a block diagram for measuring the receive sensitivity of the transmit and receive path.
Referring to FIG. 1, the base station 100 comprises a transmit and receive antenna 111 for transmitting and receiving 1FA, 2FA, and 3FA at the path A 110, a duplexer 113, an HPA (High Power Amplifier) 114, and a first LNA (Low Noise Amplifier) 115. In addition, a first coupler 112 for measuring the sensitivity is coupled to the transmit and receive antenna 111.
The path B 120 for a diversity path comprises a receive antenna 121, a second coupler 122, a filter 123, and a second LNA 124.
The transmit and receive antenna 111 of the path A 110 transmits and receives data through three frequencies of 1FA, 2FA, and 3FA to thus form a transmit and receive path. In this instance, the duplexer 113 couples the HPA 114 to the transmit and receive antenna 111 at the time of transmission, and couples the transmit and receive antenna 111 to the first LNA 115, thereby modifying the data path according to transmission and reception.
The first coupler 112 is previously combined with the transmit and receive antenna 111 so as to test the performance of the transmit and receive path, and extracts signals transmitted to and received from the path A 110 of the base station 100 according to the coupling effect so as to calculate the measured receive sensitivity.
The path B 120 is a receive-only path for the diversity path of the transmit and receive antenna 111 of the path A 110, and it transmits the data received at the receive-only antenna 121 to the second LNA 124 through the filter 123, and the receive-only antenna 121 includes a second coupler 122.
In order to measure the receive sensitivity of the path A 110 which is a transmit and receive path and the path B 120 which is a transmit-only path, a receive sensitivity jg 130 coupled to EQP (Equivalence Point Titration) ports of the first and second couplers 112 and 122 is provided
In order to process the receive sensitivity of the path A 110 of the base station 100 in the above configuration, the receive sensitivity jg 130 coupled to the EQP port of the first coupler 112 establishes a lowest signal level which can be received when the base station 100 is normally operated through data transmission and reception with the path A, and transmits the established lowest level signal to the base station 100.
When normally receiving the lowest level signal transmitted by the receive sensitivity jg 130, the path A 110 of the base station 100 can measure errors of the path of from the receive sensitivity jg 130 to the initial receive terminal of the path A, and the receive sensitivity using the lowest level signal transmitted by the receive sensitivity jg 130.
However, since the path B 120 is a receive-only path as described above, communication with the receive sensitivity jg 130 is impossible, and it is also impossible to establish the lowest level signal. Accordingly, it is difficult to measure the receive sensitivity of the path B 120, and the service may be interrupted during a measuring process.